Safe Speed Forums

Cycling in cities is bad for your health, warns heart doc
Pollution levels inside cars are often higher than that of city air because pollutants become trapped within vehicles. Cyclists sit higher than motorists and so it's generally thought they breathe in less pollutants than motorists, and expel them quicker thanks to stronger lungs. But new lab research by the British Heart Foundation attempts to show that cyclists are doing themselves more harm than good by pedalling along congested roads. The lead researcher wants cyclists off the road, and on to cycle paths away from traffic. (But wearing smog masks is fruitless, say experts, as diesel pollutant nanoparticles still get through).
If cycle paths were located away from roads the health risks would be greatly reduced, reported The Sunday Times yesterday. At 10 metres from traffic, pollution levels drop by 90 percent.

The newspaper carried an interview with David Newby, British Heart Foundation senior lecturer in cardiology at Edinburgh University. He said cycling in cities is "bad for the heart."

Newby is author of a paper soon to be published by medical magazine Circulation.

"Cycling through congested traffic exposes the cyclist to high levels of air pollution, especially as the exercise of cycling increases breathing and the individual's exposure," said Newby.

The heart doc had 15 healthy men cycle on exercise bikes for an hour while being exposed to levels of diluted diesel exhaust comparable to the air they would inhale cycling on a congested city road.

Six hours after exposure to the fumes, damage was detected to the men's blood vessels.

Instead of calling for restrictions on car use, Dr Newby wants cyclists off the roads:

"While they are exercising, cyclists breathe two to three times as much air as car drivers. We need to locate cycle lanes away from major roads."

According to the Sunday Times, the British Committee on the Medical Effects of Air Pollutants, a government advisory body, will publish a report next month highlighting the risks of heart disease from traffic pollution.

Jon Ayres, professor of environmental and occupational medicine at Aberdeen University and chairman of the committee, said:

"Exercising outside (in cities) will be a contributory cause of heart disease in healthy individuals."

This was a lesser factor than a person's blood pressure or cholesterol level but "of the same order as passive smoking," said the professor.

Research not bad news for cyclists
Currently there is no proven link between pollution and heart disease. But to better understand how it might cause problems, the BHF has funded Dr David Newby at the Univeristy of Edinburgh to look at this in detail.

The BHF stresses that the research is not bad news for cyclists in cities. For most cyclists, the benefits to their heart health from regular exercise far outweighs risk from pollution, which has yet to be directly proven.

Cycling is a great way to keep fit, and combined with a balanced diet rich in fruit and vegetables, can help keep your heart healthy.

We are a long way from proving a link between heart attacks and pollution but the results of the research will help us better understand which microscopic particles in exhaust fumes could cause problems. Armed with these results we will be in a better position to protect cyclists in the future.

Probably shouldn't believe everything you read.

We are a long way from proving a link between heart attacks and pollution

Now stop that - the NHS will soon get the idea that it can kill off pensioners by getting councils to send out high council tax bills next year and reduce the spend on OAPs